Certain authentication systems, such as those found in various logon processes for network or computer systems, may be based at least in part on the use of biometric information to authenticate a user. Biometric information generally includes physiological features of a user seeking access to the system and/or behavioral features of the user. For instance, physiological features include facial features, fingerprints, and/or retina features. Behavioral features include the behavior of the user, such as voice, gait, among other features.
In authentication systems based on facial recognition, unauthorized users may seek to circumvent these safeguards by using an image (e.g., physical photo, electronic image, such as a cell phone image, etc.) of the authorized user to spoof the system into permitting access. Hence it is important for authentication systems to distinguish between the actual user and one pretending to be the user.